iOS 7 is more particular with enum comparisons. The issue is that you're comparing an NSStreamStatus enumerated value to another, unrelated NSInputStreamEvent value. Instead, try:
NSInputStream *inputStream = [NSInputStream inputStreamWithFileAtPath:sourcePath];
if ([inputStream streamStatus] == NSStreamStatusError){
[...]
}
This issue has nothing to do with iOS 7 per se, it's just an existing issue you've now discovered thanks to more meticulous warnings.